Various methods for purifying water and for controlling the population level of biofouling and microorganisms have been disclosed. U.S. Pat. No. 5,662,940 relates to biocidal methods and compositions for recirculating the water system, comprising a hypochlorite donor and a bromide donor. This patent specifically relates to the disinfection of water in cooling towers, swimming pools and spas.
U.S. Pat. No. 5,424,032 describes a method of treating water using innocuous chemicals for the treatment of microorganisms.
The oxidizing biocide including free halogens, or hypohalites, or salts of hypohalites or hypohalite ion OX wherein X is Cl or Br, and halohydantoins such as bromochloro- or dibromodimethyl hydantoins or any oxidants which are used for disinfecting water.
When the treated water is salty water and mineral water, the disinfection agent causes a discoloration of the water which acquires a yellowish tinge, as well as a sensible turbidity thereof.
U.S. Pat. No. 4,385,973 relates to a process for disinfecting swimming pool water which comprises circulation with a pump by anodic oxidation in a reactor.
The use of anodic oxidation for the disinfection of liquids is known, for example, from U.S. Pat. No. 2,757,854, in which water that is to be disinfected is passed through a reactor which is provided with electrodes, and the water is treated electrochemically. The factors affecting the degree of disinfection are the electrical current density, the volumetric flow rate of the water, and the chloride content of the water.
It is customary to treat biologically contaminated water with one or more biocides to control the population of microorganisms in the water to prevent biofouling. Several factors play a role in the process: water pH, water temperature, aerobic/anaerobic conditions and salinity of the water. The particular types of microorganisms and the extent of microbial growth depend on the water source, and other factors.
It is a purpose of this invention to provide a process and composition for controlling biofouling and microorganism population levels in swimming pool waters, especially in salty swimming pools and salty mineral water.
It is another purpose of the invention to provide such a process and composition that have a high disinfecting effect, and to provide salty water which contains minerals, such as Fe.sup.2+, Mn.sup.2+, and Mg.sup.2+ and other minerals, which is transparent and clear water.
Oxidizing biocides were found to be effective in salty water containing a concentration of oxidants much higher than usual, and when the hydrogen peroxide concentration is increased, the oxidants' effect is decreased.
Other elements which cause coloration of the water and turbidity in the presence of oxidants are used for disinfection.